diff options
| author | David S. Miller <davem@davemloft.net> | 2008-09-16 14:11:43 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-09-16 14:11:43 -0700 |
| commit | 2e57572a50a4de41c6cbc879a4866a312d4cd316 (patch) | |
| tree | c4f58ec96c06642c4b415b881d3f0a3b673d5b44 /arch/x86/kernel/hpet.c | |
| parent | 9b2e43ae4e9609f80034dfe8de895045cac52d77 (diff) | |
| parent | f948cc6ab9e61a8e88d70ee9aafc690e6d26f92c (diff) | |
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6
Conflicts:
arch/sparc64/kernel/pci_psycho.c
Diffstat (limited to 'arch/x86/kernel/hpet.c')
| -rw-r--r-- | arch/x86/kernel/hpet.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c index 59fd3b6b1303..73deaffadd03 100644 --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -210,8 +210,8 @@ static void hpet_legacy_clockevent_register(void) /* Calculate the min / max delta */ hpet_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF, &hpet_clockevent); - hpet_clockevent.min_delta_ns = clockevent_delta2ns(0x30, - &hpet_clockevent); + /* 5 usec minimum reprogramming delta. */ + hpet_clockevent.min_delta_ns = 5000; /* * Start hpet with the boot cpu mask and make it @@ -270,15 +270,22 @@ static void hpet_legacy_set_mode(enum clock_event_mode mode, } static int hpet_legacy_next_event(unsigned long delta, - struct clock_event_device *evt) + struct clock_event_device *evt) { - unsigned long cnt; + u32 cnt; cnt = hpet_readl(HPET_COUNTER); - cnt += delta; + cnt += (u32) delta; hpet_writel(cnt, HPET_T0_CMP); - return ((long)(hpet_readl(HPET_COUNTER) - cnt ) > 0) ? -ETIME : 0; + /* + * We need to read back the CMP register to make sure that + * what we wrote hit the chip before we compare it to the + * counter. + */ + WARN_ON((u32)hpet_readl(HPET_T0_CMP) != cnt); + + return (s32)((u32)hpet_readl(HPET_COUNTER) - cnt) >= 0 ? -ETIME : 0; } /* |